Hydrostat for portable gas range

ABSTRACT

Provided is a hydrostat for a portable gas range, which prevents the explosion of a gas container by automatically discharging overcompressed gas from the gas container when the inner pressure of the gas container increases to an explosion pressure. The hydrostat includes a body including a gas outlet, which communicates with a gas inlet of the governor valve, and a sealed room, which communicate with the gas outlet. An opening/closing unit is installed within the sealed room of the body such that it can elastically move up and down in order to discharge overcompressed gas by opening the gas outlet when the inner pressure of the gas container reaches or exceeds a threshold value of deformation. A cap is fixed at the bottom of the body so as to support the opening/closing unit and has a discharge hole for discharging overcompressed gas, which escapes the gas container through the gas outlet.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/KR02/00698 which has an InternationalFiling Date of Apr. 17, 2002, which designated the United States ofAmerica.

BACKGROUND OF THE INVENTION

The present invention relates to a hydrostat for a portable gas range,and more particularly, to a hydrostat for automatically discharging gas,which is overcompressed into a gas container installed in a portable gasrange when the inner pressure of the gas container continuouslyincreases due to a radiant heat even after gas flow is usually blockedby a container-detaching safety device extinguishing a fire when anabnormal pressure occurs within the gas container, thereby preventingthe gas container from exploding.

Generally, gas ranges are widely used when preparing a light meal ordish outdoors or indoors. Due to portability and convenience, the numberof gas range users and the possible uses of gas ranges have increased.Accordingly, various safety devices have been developed to reduceaccidents associated with gas ranges.

As shown in FIGS. 1 through 3, a general portable gas range 1 includes acontainer guide 5 which guides a gas container 3 in association with thedown motion of an installing/detaching lever 2 so that the gas container3 is installed to a governor valve 4 in a horizontal direction. Theportable gas range 1 also includes a spark plug 6, a control lever 7 forcontrolling the strength of spark and combustion, a burner 8 forproviding flames, and a cover 9 for covering the gas container 3. Asshown in FIG. 2, when the installing/detaching lever 2 is pulled down,the container guide 5 moves forward so that the gas container 3 isinstalled to the governor valve 4. When the installing/detaching lever 2is pushed up, the container guide 5 moves backward so that the gascontainer 3 is detached from the governor valve 4.

When the inner pressure of the gas container 3 reaches a dangerouslevel, the installing/detaching lever 2 moves up due to the operation ofa container-detaching safety device, so the container guide 5 movesbackward detaching the gas container 3 from the governor valve 4,thereby preventing the overpressure of the gas container 3. As shown inFIG. 3, in a state in which the gas container 3 is detached from thegovernor valve 4, when the inner pressure of the gas container 3 reachesa deforming pressure due to a radiant heat, a deformable portion 3 a,which is provided at the top of the gas container 3, swells so that theoutlet of the gas container 3 closely contacts the governor valve 4. Inthe case of a flow-blocking type portable gas range, when the innerpressure of a gas container reaches a dangerous level, the flow path ofa governor valve is blocked by the operation of a flow-blocking safetydevice to prevent overpressurization of the gas container.

However, the present invention provides a hydrostat for the portable gasrange 1 to prevent the gas container 3 from exploding by automaticallydischarging overcompressed gas from the gas container 3, when the innerpressure of the gas container 3 continuously increases to a thresholdvalue of deformation, even after gas flow is primarily blocked by anexisting safety device and a fire may have been extinguished.

Generally, when gas is supplied from a gas container to a portable gasrange, the temperature of the gas container decreases due to the latentheat of vaporization, which is generated by gas absorbing surroundingheat while vaporizing, such that the probability of a gas explosion dueto an increase in temperature is low.

However, since a cooker mounted on a portable gas range is heated, aradiant heat from the bottom of the cooker may be transmitted to a gascontainer. Here, when the radiant heat is more than the latent heat ofvaporization, which is taken away from the gas container while the gasof the gas container vaporizes, heat corresponding to a differencebetween the radiant heat and the latent heat of vaporization isaccumulated at the gas container, thus increasing the temperature of thegas container. Expansion of gas due to the increase of the temperatureresults in an increase in the inner pressure of the gas container.

In the Republic of Korea, only portable gas ranges, in which gas flow isautomatically blocked for extinguishing a fire when the inner pressureof a gas container is in a range of 5–7 kg/cm², are permitted to bemanufactured and sold. In Japan, only portable gas ranges, in which gasflow is automatically blocked for extinuishing a fire when the innerpressure of a gas container is in a range of 4–6 kg/cm², are permittedto be manufactured and sold.

To block the gas flow, there is provided a safety device. In theRepublic of Korea, a container-detaching safety device blocks the gasflow by detaching a gas container from the inlet of a governor of aportable gas range when the inner pressure of the gas container is in arange of 5–7 kg/cm². In Japan, a flow-blocking safety device blocks thegas flow by blocking a flow path within a governor of a portable gasrange when the inner pressure of a gas container is in a range of 4–6kg/cm². The container-detaching type is mainly used in the Republic ofKorea, and the flow-blocking type is mainly used in Japan.

These safety devices are provided for preventing the explosion of a gascontainer due to an increase in the inner pressure of the gas container,which results from the expansion of gas that occurs when the temperatureof the gas container is increased by accumulation of heat correspondingto the difference between a radiant heat and the latent heat ofvaporization where the radiant heat is more than the latent heat ofvaporization.

For example, it is defined that the normal pressure of a butane gascontainer used in a portable gas range is in a range of 2–3 kg/cm², theprimary deforming pressure of the gas container is 13 kg/cm², and thesecondary deforming pressure of the gas container is 15 kg/cm². In otherwords, it is regulated that the gas container be manufactured to notexplode until the inner pressure of the gas container reaches 15 kg/cm².Accordingly, an explosion of the gas container can be prevented byblocking the flow of gas at the inner pressure of 5–7 kg/cm² andextinguishing a fire when the inner pressure of the gas containerincreases due to a radiant heat in order to prohibit the inner pressureof the gas container from increasing to the threshold value ofexplosion.

As shown in FIGS. 4 and 5, a body 11 of a flow-blocking safety deviceincludes an inlet 11 a which a gas container 3 is installed to ordetached from; a chamber 12 for maintaining the gas pressure, which issupplied to a burner, constant; a control lever 14 for controlling thevolume of gas supplied to the burner; and a flow path for connecting theinlet 11 a, the chamber 12, and the control lever 14.

A gas blocking unit 50 for blocking the flow path when a gas pressureexceeds a reference value is provided in the flow path between the inlet11 a and the chamber 12. A pressure control unit 30 for maintaining thepressure of gas, which is supplied to a burner, constant is installedwithin the chamber 12. The gas blocking unit 50 is composed of a taperhole 51 whose diameter decreases toward the back of the flow path, acylinder hole 52 which straightly communicates with the taper hole 51, ablocking valve 53 which is installed within the taper hole 51 and thecylinder hole 52 and is moved backward by the pressure of gas, and aplate spring 54 which elastically supports the back of the blockingvalve 53. The plate spring 54 contacts a return valve 55 whose one endis exposed to the outside. A return lever 56, which slides up and downand pushes forward the return valve 55, is installed outside above thereturn valve 55.

The blocking valve 53 is composed of a blocking portion 57, which islocated in front of the taper hole 51, and an operating portion 58,which is located within the cylinder hole 52. An O-ring is installedaround the outer circumference of the blocking portion 57 in order tohermetically seal the taper hole 51 when the blocking valve 53 movesbackward, and an O-ring is installed around the outer circumference ofthe operating portion 58 in order to prevent the leakage of gas.

In addition, a nozzle 59 communicating with the chamber 12 is providedat one side of the cylinder hole 52 in front of the operating portion58.

The pressure control unit 30 includes a rubber plate 31 which ishermetically sealed in an upper portion of the chamber 12; a spring 32which presses down the rubber plate 31; a needle holder 33 which isconnected to the rubber plate 31; and a needle valve 35, which isconnected to the body 11 via a hinge at the center, is connected to theneedle holder 33 at one end, and has a stopper 34 for closing andopening the nozzle 59 at the other end.

Accordingly, when a user turns on the gas range, gas within the chamber12 is supplied to the burner, decreasing the gas pressure within thechamber 12, so the rubber plate 31 is pressed by the spring 32separating the needle valve 35, which is hinge-connected to the body 11,from the nozzle 59 so that gas in a gas container flows into the chamber12.

When the pressure of gas flowing into the chamber 12 exceeds apredetermined value, the rubber plate 31 overcomes the elasticity of thespring 32 and is lifted up so that the needle valve 35 blocks the nozzle59.

In addition, when the gas pressure exceeds a reference value due to theoverheating of the gas container, the blocking valve 53 overcomes theelasticity of the plate spring 54 and moves backward blocking the taperhole 51 so that gas supply is interrupted and the fire of the burner isextinguished.

The above-described flow-blocking safety device cannot cope with a rapidincrease of pressure within the gas container, which still remainswithin the gas range after the gas supply is interrupted primarily, dueto a radiant heat occurring after the heat of vaporization, which isgenerated when liquefied gas within the gas container vaporizes.

In many cases, the explosion of a gas container has been prevented byinterrupting the gas supply at a dangerous pressure level. However,there have been constant accidents where a gas container explodes evenafter a safety device operates.

Recently, an approach for preventing the explosion of a gas containerwas disclosed in Korean Patent Application No. 2000-0065187.

FIG. 6 is a side-sectional view of a safety device for a portable gasrange, as disclosed in Korean Patent Application No. 2000-0065187. Thesafety device further includes a gas discharge unit 60 in addition to aflow-blocking safety device for a portable gas range. The gas dischargeunit 60 is composed of a housing 61 which includes a through-hole 61 acommunicating with a flow path and a discharge hole 61 b for discharginggas outside; and a safety bar 63 which is elastically supported by aspring 62 so that it closely contacts the through-hole 61 a.

A cylinder hole 64 is provided within the housing 61. The through-hole61 a is provided at one end of the cylinder hole 64, and a circular cap65 is screw-connected to the other end of the cylinder hole 64. Thedischarge hole 61 b is provided at the circumferential wall of thecylinder hole 64 near the through-hole 61 a, and a nozzle 66 extendingoutside is connected to the discharge hole 61 b.

The safety bar 63 is composed of a piston portion 63 a, which isinserted into the cylinder hole 64 within the housing 61 so that it ismoved by a gas pressure; and a sealing portion 63 b, which closelycontacts the through-hole 61 a. The spring 62 supported by the innerwall of the cap 65 is provided at the back of the safety bar 63.

Accordingly, as described above, when the pressure of gas within thechamber 12 exceeds a predetermined value, the needle valve 35 of thepressure control unit 30 blocks the nozzle 59, primarily interruptingthe gas supplied to the chamber 12. Continuously, the gas container isoverheated increasing the pressure of supplied gas over the referencevalue. Then, the plate spring 54 operates to secondarily interrupt thegas supply so that the fire of the burner is extinguished.

In this state, when the gas pressure of the gas container exceeds apredetermined value, for example, 13–15 kg/cm², due to a fire occurringnear the gas range or a latent heat which is accumulated in the gasrange or the gas container, the safety bar 63 of the gas discharge unit60 overcomes the elasticity of the spring 62 and moves backward openingthe through-hole 61 a. As a result, gas within the gas container isdischarged outside through the nozzle 66, decreasing the inner pressureof the gas container. Accordingly, even if the gas container iscontinuously overheated, it can be safely used without exploding.

However, in this conventional embodiment, since the housing 61 is formedto have the through-hole 61 a extending from the taper hole 51, thestructure is complicated. In addition, since the gas discharge unit 60protrudes from the side of the body 11, the volume of the body 11increases, which requires a structural change in a usual portable gasrange.

Since the through-hole 61 a of the housing 61 is not simply a gaspassage but is mechanically connected to a primary safety device, whichis operated by the plate spring 54, it is necessary to separatelymanufacture the housing 61 from the body 11 in order to operate theblocking portion 57 using the spring 58 a. Accordingly, a process ofassembling the body 11 and the housing 61 is additionally needed.

Moreover, the discharge hole 61 b needs to be formed within the gasrange so that gas is discharged preferably downward or outside using aconnection pipe. For this, the extra nozzle 66 must be formed, so theentire structure of the safety device becomes complicated.

In the case of the container-detaching safety device for detaching a gascontainer from a gas range, since an external mechanical unit needs tobe installed, the ratio of defective products to finished products ishigh. When it is used for a long term, an operating portion easilycorrodes or is easily contaminated with foreign substances, so thesafety device does may not operate even if the inner pressure of the gascontainer increases to a dangerous value.

Moreover, the container-detaching safety device, which detaches the gascontainer using the external unit, requires a great power to forciblydetach the gas container and also increases in size.

Although the latent heat of vaporization disappears shortly after acontainer-detaching safety device or a flow-blocking safety deviceblocks the path of gas flow so as to extinguish a fire when the pressureof a gas container increases over a predetermined value, the gascontainer totally absorbs a radiant heat from a cooker, such as a fryingpan, even after the fire is extinguished, so the pressure of the gascontainer rapidly increases. As a result, the inner pressure of the gascontainer exceeds a primary container deformation pressure and reaches asecondary container explosion pressure, exploding the gas container.

The use of larger cookers may further increase the chances for containerexplosion. According to “(5-1) The use of a larger cooker than a tripod”at “Paragraph 5—The Incidents Related to Portable Butane Burners(Portable Gas Ranges) and Combined Containers (Butane Gas Containers)”of the Gas Incident Yearbook (Chapter 4, pp. 185, 2000) published byKorea Gas Safety Corporation, the cause of some incidents occurs since alarger cooker than the tripod of a portable butane burner was used. Thecombined container installed in the burner was heated by a radiant heatand exploded due to an increase in the inner pressure thereof. Forexample, while meat was being roasted using a portable butane burner, anoverpressure cutoff of the burner operated, and after a short time, abutane can exploded with a bang sound.

This report indicates that a gas container exploded even when anexisting safety device operated normally. In other words, the fact thatthe gas container exploded with a bang sound after the existing safetydevice operated suggests that while the latent heat of vaporizationdisappears after gas flow is blocked, a radiant heat is still applied tothe gas container rapidly increasing the inner pressure of the gascontainer over a deforming pressure to an explosion pressure, so the gascontainer explodes. Consequently, it further suggests that existingsafety devices cannot fundamentally prevent explosion of a gascontainer.

Accordingly, development of a new safety device for fundamentallypreventing the explosion of a gas container in a portable gas range isdesired.

SUMMARY OF THE INVENTION

To solve the above problems, the present invention provides a hydrostatfor preventing the explosion of a gas container in a gas range.

The present invention provides a hydrostat for preventing the explosionof a gas container in a portable gas range even if the inner pressure ofthe gas container increases due to a radiant heat continuously appliedto the gas container after gas flow is blocked by a container-detachingsafety device.

The present invention provides a hydrostat for a portable gas range,which has a simple structure, operates simply, and is applied in variousways.

In an exemplary embodiment, there is provided a hydrostat for a portablegas range, which includes a container-detaching safety device forautomatically detaching a gas container to interrupt gas flow andextinguish a fire when the inner pressure of the gas container reaches adangerous value or a flow-blocking safety device for blocking the pathof gas flow with the gas container still installed to extinguish a firewhen the inner pressure of the gas container reaches a dangerous value.The hydrostat includes a body comprising a gas outlet, whichcommunicates with a gas inlet of the governor valve, and a sealed room,which communicates with the gas outlet; an opening/closing unit which isinstalled within the sealed room of the body such that it canelastically move up and down in order to discharge overcompressed gas byopening the gas outlet when the inner pressure of the gas containerreaches at least a threshold value of deformation or explosion; and acap which is fixed at the bottom of the body so as to support theopening/closing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a structure of a conventional portable gas range.

FIG. 2 is a plan view of a state in which a gas container is installedin or detached from the gas range shown in FIG. 1.

FIG. 3 is a plan view of a state in which a detached gas container isdeformed and closely contacts a governor valve.

FIG. 4 is a side sectional view of a conventional flow-blocking typeportable gas range.

FIG. 5 is a front view of the portable gas range shown in FIG. 4.

FIG. 6 is a front view of a conventional hydrostat for a portable gasrange.

FIG. 7 is an exploded perspective view of a hydrostat for a portable gasrange according to a first embodiment of the present invention.

FIG. 8 is a front view of the hydrostat shown in FIG. 7.

FIG. 9 is a side sectional view of the hydrostat shown in FIG. 7.

FIG. 10 is an exploded perspective view of a hydrostat for a portablegas range according to a second embodiment of the present invention.

FIG. 11 is a partial sectional view of the hydrostat shown in FIG. 10.

FIG. 12 is a partial sectional view of a hydrostat for a portable gasrange according to a third embodiment of the present invention.

FIG. 13 is a partial sectional view of a hydrostat for a portable gasrange according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred exemplary embodiments of the present inventionwill be described with reference to the attached drawings.

Referring to FIGS. 7 through 9, a hydrostat for a portable gas rangeaccording to a first embodiment of the present invention includes a body70 which is installed below a governor valve 4 of the gas range.Preferably, the body 70 has a cylindrical shape and includes a gasoutlet 72, which communicates with a gas inlet 4 a, and a sealed room74, which communicates with the gas outlet 72. Particularly, the body 70of the hydrostat according to the first embodiment may be formed as oneleg among a plurality of legs for supporting the entire gas range.

An opening/closing unit 80 is installed to be movable up and down withinthe sealed room 74 of the body 70 in order to selectively open or closethe gas outlet 72, more specifically, in order to open the gas outlet 72when the inner pressure of a gas container exceeds a threshold value ofdeformation or a threshold value of explosion. The opening/closing unit80 includes a sealing shaft 82 which is installed to be movable up anddown within the sealed room 74 of the body 70. A circular support plate84 is provided at the top of the sealing shaft 82. A sealing member 86for actually opening or closing the gas outlet 72 is attached or mountedon the support plate 84. An elastic member 88 for elastically supportingthe sealing shaft 82 is provided surrounding the sealing shaft 82 suchthat the sealing shaft 82 can move up and down. Preferably, the elasticmember 88 is manifested as a compressive spring whose top end contactsand is fixed on the bottom of the support plate 84. Particularly, it ispreferable that the elasticity or tension of the compressive spring asthe elastic member 88 is greater than a dangerous pressure (for example,5–7 kg/cm² or 4–6 kg/cm²), at which usual safety devices operate, andsmaller than a container deformation pressure or container explosionpressure.

A cap 90 is removably installed at the bottom of the body 70 in order toopen or close the sealed room 74 of the body 70 and support the bottomend of the elastic member 88 of the opening/closing unit 80. The cap 90includes a coupling portion 92, which is removably, for example,screw-coupled with the bottom portion of the body 70 to support thebottom portion of the elastic member 88, and a handle 94, which isintegrated with the coupling portion 92 so that a user can hold and turnthe cap 90. A guide hole 96 is formed at the center of the cap 90 suchthat it pierces through the cap 90 in a shaft direction. The bottomportion of the sealing shaft 82 of the opening/closing unit 80 isinserted into the guide hole 96 so that the up and down movement of thesealing shaft 82 is guided. Preferably, discharge holes 98 are formed atthe side of the guide hole 96 in a lengthwise direction in order todischarge gas from a gas container.

Selectively, one or more discharge holes 70 a communicating with thesealed room 74 may be formed at the lower portion of the body 70 todischarge gas from a gas container. Preferably, a plurality ofprotruding legs 90 a are formed on the outer surface of the cap 90 sothat the outer surface of the cap 90 can be separated from the ground inorder to allow gas to be easily discharged through the discharge holes98.

Referring to FIGS. 10 and 11, a hydrostat according to a secondembodiment of the present invention has a similar structure to the abovefirst embodiment. Thus, reference numerals between 100 and 200 are usedto distinguish the second embodiment from the first embodiment. Thehydrostat for a portable gas range according to the second embodiment ofthe present invention includes a body 170 which is installed below thegovernor valve 4 of the gas range. Preferably, the body 170 has acylindrical shape and includes a gas outlet 172, which communicates withthe gas inlet 4 a, and a sealed room 174, which communicates with thegas outlet 172. Particularly, a rounding process is performed on thedischarging portion of the gas outlet 172, that is, a contact portionbetween the gas outlet 172 and the sealed room 174. The body 170 of thehydrostat according to the second embodiment may be formed as one legamong a plurality of legs for supporting the entire gas range.Selectively, one or more discharge holes (not shown) communicating withthe sealed room 174 may be formed at the lower portion of the body 170to discharge gas from a gas container.

An opening/closing unit 180 is installed to be movable up and downwithin the sealed room 174 of the body 170 in order to selectively openor close the gas outlet 172. The opening/closing unit 180 includes asealing shaft 182 which is installed to be movable up and down withinthe sealed room 174 of the body 170. Particularly, the sealing shaft 182is much shorter than the sealing shaft 82 of the first embodiment. Acircular support plate 184 is provided at the top of the sealing shaft182 and has a protruding keeper 184 a. A sealing member 186 for actuallyopening or closing the contact portion of the gas outlet 172 is keptaround and fixed at the keeper 184 a of the support plate 184.Preferably, the sealing member 186 is made of an elastic material suchas rubber and has a ring shape with a keeping hole 186 a, through whichthe keeper 184 is inserted. The upper portion of an elastic member 188for elastically supporting the sealing shaft 182 is provided surroundingthe sealing shaft 182 such that the sealing shaft 182 can move up anddown. Preferably, the upper portion of the elastic member 188 has theinside diameter which is similar to or the same as the outside diameterof the sealing shaft 182 and is manifested as a compressive spring whosetop end contacts and is fixed on the bottom of the support plate 184. Itis also preferable that the elasticity or tension of the compressivespring as the elastic member 188 is greater than a dangerous pressure(for example, 5–7 kg/cm² or 4–6 kg/cm²), at which usual safety devicesoperate, and smaller than a container deformation pressure or containerexplosion pressure.

A cap 190 is removably installed at the bottom of the body 170 in orderto open or close the sealed room 174 of the body 170 and support thebottom end of the elastic member 188 of the opening/closing unit 180.The cap 190 includes a coupling portion 192, which is removably, forexample, screw-coupled with the bottom portion of the body 170, and ahandle 194, which is integrated with the coupling portion 192 so that auser can hold and turn the cap 190. Particularly, a keeper 192 a isintegrally formed at the coupling portion 192 of the cap 190 such thatthe bottom portion of the elastic member 188 is fixed at or is installedsurrounding the keeper 192 a. A discharge hole 198 is formed at thecenter of the cap 190 in a lengthwise direction in order to dischargegas from a gas container. A plurality of protruding legs 190 a may beformed on the outer surface of the cap 190 so that the outer surface ofthe cap 190 can be separated from the ground in order to prevent thedischarge hole 198 from being blocked by the ground.

Referring to FIG. 12, a hydrostat for a portable gas range according toa third embodiment of the present invention has a similar structure tothe above first and second embodiments. Thus, reference numerals between200 and 300 are used to distinguish the third embodiment from the firstand second embodiments. The hydrostat according to the third embodimentof the present invention includes a body 270 which is installed belowthe governor valve 4 of the gas range. Preferably, the body 270 has acylindrical shape and includes a gas outlet 272, which communicates withthe gas inlet 4 a, and a sealed room 274, which communicates with thegas outlet 272. Particularly, the body 270 of the hydrostat according tothe third embodiment may be formed as one leg among a plurality of legsfor supporting the entire gas range. Selectively, a discharge hole 270 acommunicating with the sealed room 274 may be formed at the lowerportion of the body 270 to discharge gas from a gas container.

An opening/closing unit 280 is installed within the sealed room 274 ofthe body 270 such that it can move up and down within the sealed room274 in order to selectively open or close the gas outlet 272. Theopening/closing unit 280 includes a sealing shaft 282 which is installedto be elastically movable up and down within the sealed room 274 of thebody 270. A circular support plate 284 is provided at the top of thesealing shaft 282. A sealing member 286, which is made of an elasticmaterial such as rubber for actually opening or closing the gas outlet272, is attached or mounted on the support plate 284. An elastic member288 for elastically supporting the sealing shaft 282 is provided at thebottom of the sealing shaft 282 such that the sealing shaft 282 can moveup and down. Preferably, the elastic member 288 is manifested as a platespring. As in the first and second embodiments, it is also preferablethat the elasticity or tension of the plate spring as the elastic member288 is greater than a dangerous pressure (for example, 5–7 kg/cm² or 4–6kg/cm²), at which usual safety devices operate, and smaller than acontainer deformation pressure or container explosion pressure.

A cap 290 is removably installed at the bottom of the body 270 in orderto open or close the sealed room 274 of the body 270 and support theelastic member 288 of the opening/closing unit 280. The cap 290 includesa coupling portion 292, which is removably, for example, screw-coupledwith the bottom portion of the body 270 and has a keeping groove 292 afor elastically receiving the elastic member 288 therein; and a handle294, which is integrated with the coupling portion 292 so that a usercan hold and turn the cap 290. Selectively, although not shown, adischarge hole may be formed in the cap 290 in order to discharge gasfrom a gas container. In addition, a plurality of protruding legs (notshown) may be formed on the outer surface of the cap 290 so that theouter surface of the cap 290 can be separated from the ground in orderto allow gas to be easily discharged through the discharge hole.

Referring to FIG. 13, a hydrostat for a portable gas range according toa fourth embodiment of the present invention also has a similarstructure to the above first, second, and third embodiments. Thus,reference numerals between 300 and 400 are used to distinguish thefourth embodiment from the first through third embodiments. Thehydrostat for a portable gas range according to the fourth embodiment ofthe present invention includes a body 370 which is installed below thegovernor valve 4 of the gas range. Preferably, the body 370 has acylindrical shape and includes a gas outlet 372, which communicates withthe gas inlet 4 a, and a sealed room 374, which communicates with thegas outlet 372. Particularly, the body 370 of the hydrostat according tothe fourth embodiment may be formed as one leg among a plurality of legsfor supporting the entire gas range.

An opening/closing unit 380 is installed to be movable up and downwithin the sealed room 374 of the body 370 in order to selectively openor close the gas outlet 372, more specifically, in order to open the gasoutlet 372 when the inner pressure of a gas container exceeds athreshold value of deformation or a threshold value of explosion. Theopening/closing unit 380 includes a sealing shaft 382 which is installedto be movable up and down within the sealed room 374 of the body 370. Acircular support plate 384 is provided at the upper portion of thesealing shaft 382. In addition, a support groove 382 a is formed at thetop portion of the sealing shaft 382. Preferably, the supporting groove382 a has a reversed-cone shape. A sealing member 386 for actuallyopening or closing the gas outlet 372 is supported by the support groove382 a. The sealing member 386 is composed of a reversed-cone-shapedsupport piece 386 a, which is supported by the support groove 382 a, anda seal piece 386 b, which is made of an elastic material such as rubberand is fixed at the top of the support piece 386 a in order toselectively open or close the gas outlet 372 of the body 370. An elasticmember 388 for elastically supporting the sealing shaft 382 is installedsurrounding the sealing shaft 382 such that the sealing shaft 382 canmove up and down. Preferably, the elastic member 388 is manifested as acompressive spring whose top end contacts the bottom of the supportplate 384. Particularly, as described in the above embodiments, it ispreferable that the elasticity or tension of the compressive spring asthe elastic member 388 is greater than a dangerous pressure (forexample, 5–7 kg/cm² or 4–6 kg/cm²), at which usual safety devicesoperate, and smaller than a container deformation pressure or containerexplosion pressure.

Particularly, when the cap 390 is screw-coupled with the body 370 in thehydrostat according to the fourth embodiment, the sealing member 386completely cover the gas outlet 372. More specifically, since thesealing member 386 is composed of the support piece 386 a, which has areversed-cone shape at the lower portion and a groove of a predeterminedshape at the upper portion, and a seal piece 386 b, which is received inthe groove of the support piece 386 a, the seal piece 386 b can exactlycontact the gas outlet 372 without distortion. Consequently, in such astructure, when the cap 390 is screw-coupled with the body 370, whilethe sealing shaft 382 simultaneously performs a rotating motion and avertical rectilinear motion, the sealing member 386 performs only avertical rectilinear motion, so the seal piece 386 b can open or closethe gas outlet 372 without distortion.

In the fourth embodiment of the present invention shown in FIG. 13, thereversed-cone-shaped support groove 382 a is formed at the top portionof the sealing shaft 382, and the lower portion of the support piece 386a of the sealing member 386 has a reversed-cone shape. However, it willbe easily understood by one of ordinary skill in the art of the presentinvention that a similar effect can be achieved by forming the sealingshaft 382 to have a cone-shaped upper portion and forming the supportpiece 386 a to have a cone-shaped groove at its bottom.

In addition, the cap 390 is removably installed at the bottom of thebody 370 not only to open or close the sealed room 374 of the body 370but also to support the bottom end of the elastic member 388 of theopening/closing unit 380. For example, the cap 390 is removablyscrew-coupled with the bottom portion of the body 370. Particularly, aplurality of discharge holes 398 are formed in the inner wall of the cap390 in a lengthwise direction such that it communicates with the sealedroom 374 of the body 370 and discharges gas from a gas container.

Selectively, although not shown, a plurality of protruding legs may beformed on the outer bottom surface of the cap 390 so that the outerbottom surface of the cap 390 can be separated from the ground in orderto allow gas to be easily discharged through the discharge holes 398.

In the above embodiments, each of the caps 90, 190, 290, and 390 isscrew-coupled with the body 70, 170, 270, or 370, so the elasticity ofthe elastic member 88, 188, 288, or 388 can be adjusted by fastening orloosening the cap 90, 190, 290, or 390. However, it will be easilyunderstood by one or ordinary skill in the art of the present inventionthat the cap may be fixed to the body, for example, by pressing the bodyaround the cap after the elasticity of the elastic member is adjusted.The reason one or more discharge holes 98, 198, or 398 are formed in alengthwise direction to face the ground is to allow butane gas, whichhas larger specific gravity than the air, to be swiftly discharged froma gas container.

In the above embodiments, the hydrostat for a portable gas rangeaccording to the present invention is installed below the governor valveof the portable gas range. However, it will be easily understood by oneof ordinary skill in the art of the present invention that in otherembodiments the hydrostat can be installed beside or above the governorvalve on condition that the body of the hydrostat communicates with thegas inlet of the governor valve.

Hereinafter, the operations and effects of the hydrostats for a portablegas range according to the above-described embodiments will be describedin detail.

The hydrostat according to the first embodiment shown in FIGS. 7 through9 is installed below the governor valve 4 of a gas range or can beimplemented as a leg of the gas range. In a normal state, that is, whenthe inner pressure of a gas container is maintained at a normal level,the gas outlet 72 of the body 70 is maintained closed due to sealingshaft 82 of the opening/closing unit 80. More specifically, the sealingshaft 82 moves upward due to the tension of the elastic member 88, sothe sealing member 86 provided at the top of the support plate 84 of thesealing shaft 82 closes the gas outlet 72. Accordingly, gas from the gascontainer passes through a gas inlet and is supplied to a burner so thatcooking can be performed normally.

In this state, for example, if a radiant heat is excessively applied tothe gas container increasing the inner pressure of the gas container toa dangerous value or over, a flow-blocking safety device primarilyoperates to block the gas flow from the nozzle 59 to the chamber 12 andextinguish the fire. Thereafter, if the inner pressure of the gascontainer reaches threshold value of deformation or a threshold value ofexplosion due to a radiant heat that is continuously applied from acooker, such as a frying pan, to the gas container, the inner pressureof the gas container becomes larger than the tension of the elasticmember 88, which supports the sealing shaft 82 to close the gas outlet72. Then, the elastic member 88 is compressed and simultaneously, thesealing shaft 82 is moved downward separating the sealing member 86 fromthe gas outlet 72. Here, the sealing shaft 82 is guided by the guidehole 96 of the cap 90 therebelow so that it can be reliably moved.

It has been described with reference to FIGS. 7 through 9 that theportable gas range employs a flow-block safety device. However, thesimilar description to the above one can be applied to a case where theportable gas range employs a container-detaching safety device. Morespecifically, when a radiant heat is excessively applied to the gascontainer, increasing the inner pressure of the gas container to adangerous value or more, the gas container is primarily detached fromthe governor valve 4 by the container-detaching safety device,interrupting the supply of gas. Thereafter, if the inner pressure of thegas container reaches threshold value of deformation or over due to aradiant heat that is continuously applied from a cooker, such as afrying pan, to the gas container, the deformable portion 3 a of the gascontainer expands and closely contacts the governor valve 4. In thisstate, if the inner pressure of the gas container continuously increasesand becomes larger than the tension of the elastic member 88, whichsupports the sealing shaft 82 to close the gas outlet 72, the elasticmember 88 is compressed and simultaneously, the sealing shaft 82 ismoved downward separating the sealing member 86 from the gas outlet 72.

By opening the gas outlet 72, overcompressed gas passes through the gasoutlet 72 and the sealed room 74 of the body 70 and is dischargedthrough the discharge hole 98. In addition, a large volume of gas can beinstantly discharged through the discharge holes 70 a formed in the body70. In the mean time, since the outer surface of the gap 90 is separatedfrom the ground, the gas can be reliably and easily discharged throughthe discharge hole 98 formed in the cap 90. When the overcompressed gasis discharged from the gas container and the inner pressure of the gascontainer returns to a normal state, the sealing shaft 82 is movedupward by the tension or elasticity of the elastic member 88 so that thesealing member 86 blocks the gas outlet 72, thereby preventing gas fromfurther escaping. As described above, overcompressed gas is dischargedfrom the gas container by the opening/closing unit 80, whichautomatically operates when the inner pressure of the gas containerexcessively increases, thereby preventing the explosion of the gascontainer.

According to the hydrostat shown in FIGS. 10 and 11 for a portable gasrange according to the second embodiment of the present invention, in anormal state as described in the first embodiment, when a radiant heatis excessively applied to a gas container, increasing the inner pressureof the gas container to a dangerous value or more, the gas container isprimarily detached from the governor valve 4 by a container-detachingsafety device, interrupting the supply of gas. Thereafter, if the innerpressure of the gas container reaches threshold value of deformation orover due to a radiant heat that is continuously applied from a cooker tothe gas container, the deformable portion 3 a of the gas containerexpands and closely contacts the governor valve 4. In this state, if theinner pressure of the gas container continuously increases and becomeslarger than the tension of the elastic member 188, which supports thesealing shaft 182 to close the gas outlet 172, the elastic member 188 iscompressed and simultaneously, the sealing shaft 182 is moved downwardseparating the sealing member 186 from the gas outlet 172.

By opening the gas outlet 172, overcompressed gas passes through the gasoutlet 172 and the sealed room 174 of the body 170 and is dischargedthrough the discharge hole 198. When the overcompressed gas isdischarged from the gas container and the inner pressure of the gascontainer returns to a normal state, the sealing shaft 182 is movedupward by the tension or elasticity of the elastic member 188 so thatthe sealing member 186 blocks the gas outlet 172, thereby preventing gasfrom further escaping. As described above, overcompressed gas isdischarged from the gas container by the opening/closing unit 180, whichautomatically operates when the inner pressure of the gas containerexcessively increases, thereby preventing the explosion of the gascontainer.

According to the hydrostat shown in FIG. 12 for a portable gas rangeaccording to the third embodiment of the present invention, in a normalstate as described in the first and second embodiments, when a radiantheat is excessively applied to a gas container, increasing the innerpressure of the gas container to a dangerous value or more, the gascontainer is primarily detached from the governor valve 4 by acontainer-detaching safety device, interrupting the supply of gas.Thereafter, if the inner pressure of the gas container reaches thresholdvalue of deformation or over due to a radiant heat that is continuouslyapplied from a cooker to the gas container, the deformable portion 3 aof the gas container expands and closely contacts the governor valve 4.In this state, if the inner pressure of the gas container continuouslyincreases and becomes larger than the tension of the elastic member 288,which supports the sealing shaft 282 to close the gas outlet 272, theelastic member 288, i.e., a plate spring, is compressed andsimultaneously, the sealing shaft 282 is moved downward separating thesealing member 286 from the gas outlet 272.

By opening the gas outlet 272, overcompressed gas passes through the gasoutlet 272 and the sealed room 274 of the body 270 and is dischargedthrough the discharge hole 270 a, which communicates with the sealedroom 274 in the body 270. When the overcompressed gas is discharged fromthe gas container and the inner pressure of the gas container returns toa normal state, the sealing shaft 282 is moved upward by the elasticityof the elastic member 288 so that the sealing member 286 blocks the gasoutlet 272, thereby preventing gas from further escaping. As describedabove, overcompressed gas is discharged from the gas container by theopening/closing unit 280, which automatically operates when the innerpressure of the gas container excessively increases, thereby preventingthe explosion of the gas container.

According to the hydrostat shown in FIG. 13 for a portable gas rangeaccording to the fourth embodiment of the present invention, in a normalstate as described in the first through third embodiments, when aradiant heat is excessively applied to a gas container, increasing theinner pressure of the gas container to a dangerous value or more, thegas container is primarily detached from the governor valve 4 by acontainer-detaching safety device, interrupting the supply of gas.Thereafter, if the inner pressure of the gas container reaches thresholdvalue of deformation or over due to a radiant heat that is continuouslyapplied from a cooker to the gas container, the deformable portion 3 aof the gas container expands and closely contacts the governor valve 4.In this state, if the inner pressure of the gas container continuouslyincreases and becomes larger than the tension of the elastic member 388,which supports the sealing shaft 382 to close the gas outlet 372, theelastic member 388 is compressed and simultaneously, the sealing shaft382 is moved downward separating the sealing member 386 from the gasoutlet 372.

By opening the gas outlet 372, overcompressed gas passes through the gasoutlet 372 and the sealed room 374 and is discharged through thedischarge holes 398, which are formed along the circumference of the cap390. When the overcompressed gas is discharged from the gas containerand the inner pressure of the gas container returns to a normal state,the sealing shaft 382 is moved upward by the tension or elasticity ofthe elastic member 388 so that the sealing member 386 blocks the gasoutlet 372, thereby preventing gas from further escaping. As describedabove, overcompressed gas is discharged from the gas container by theopening/closing unit 380, which automatically operates when the innerpressure of the gas container excessively increases, thereby preventingthe explosion of the gas container. Accordingly, even if the innerpressure of the gas container continuously increases due to a radiantheat, which is applied from a cooker to the gas container during use ofthe gas range, overcompressed gas is automatically discharged, therebyautomatically preventing the explosion of the gas container.

In the hydrostat according to the fourth embodiment, since the sealpiece 386 b of the sealing member 386 moves up and down either when theelasticity of the elastic member 388 is adjusted or when the sealingshaft 382 is installed, the sealing member 386 can exactly contact thegas outlet 372 having an even level without distortion or deformation sothat the gas outlet 372 can be hermetically sealed by theopening/closing unit 380.

In the second through fourth embodiments of the present invention shownin FIGS. 10 through 13, it has been described that the portable gasrange employs a container-detaching safety device. However, it will beeasily understood by those of ordinary skill in the art of the presentinvention that the similar description to the first embodiment one canbe applied to a case where the portable gas range employs aflow-blocking safety device in the second through fourth embodiments.

While this invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes may be made thereinwithout departing from the scope of the invention. Therefore, theabove-described embodiments will be considered not in restrictive sensebut in descriptive sense only. The scope of the invention will bedefined not by the above description but by the appended claims, and itwill be construed that all differences made within the scope defined bythe claims are included in the present invention.

Consequently, according to a hydrostat for a portable gas rangeaccording to the present invention, an opening/closing unitautomatically operates to discharge gas when the inner pressure of a gascontainer excessively increases, thereby preventing the explosion of thegas container. Therefore, the safety and quality of products can beimproved.

In addition, a hydrostat according to the present invention can beadapted to an existing portable gas range and has a simple structure,thereby increasing adaptability and productivity.

Moreover, since a hydrostat can be implemented as a leg of a portablegas range, convenience and simplicity can be improved.

1. A hydrostat for a portable gas range having a governor valve, andwhich includes at least one of either a container-detaching safetydevice for automatically detaching a gas container to interrupt gas flowand extinguish a fire when the inner pressure of the gas containerreaches a dangerous value or a flow-blocking safety device for blockingthe path of gas flow with the gas container still installed toextinguish a fire when the inner pressure of the gas container reaches adangerous value, the hydrostat comprising: a body comprising a gasoutlet, which communicates with the governor valve, and a sealed room,which communicate with the gas outlet; an opening/closing unit which isinstalled within the sealed room of the body for opening and closing thegas outlet; an elastic member for biasing the opening/closing unit intoa closed position when the inner pressure of the gas container does notexceed a threshold value and for allowing movement of theopening/closing unit to an open position to discharge gas from the gascontainer by opening the gas outlet when the inner pressure of the gascontainer reaches or exceeds the threshold value; and a cap which isfixed at the bottom of the body to support the elastic member and theopening/closing unit, wherein the opening/closing unit comprises asealing shaft with a support plate at an upper portion thereof, thesupport plate having a reverse-cone-shaped support groove at the topportion thereof; a sealing member comprising a support piece, which hasa reverse-cone-shaped bottom portion for engaging the support groove,and a seal piece for blocking the gas outlet when the opening/closingunit is in a closed position.
 2. The hydrostat of claim 1, wherein theelastic member comprises a compressive spring whose top contacts and isfixed on the bottom surface of the support plate, and the elasticity ofthe elastic member allows movement of the opening/closing member to anopen position when the inner pressure within the gas container reachesor exceeds the threshold value.
 3. The hydrostat of claim 1, wherein thebody further comprises a discharge outlet for discharging gas from thesealed room when the opening/closing unit is an open condition.
 4. Thehydrostat of claim 3, wherein the discharge outlet includes a pluralityof discharge holes disposed at one end of the body.
 5. A hydrostat for aportable gas range having a governor valve, and which includes at leastone of either a container-detaching safety device for automaticallydetaching a gas container to interrupt gas flow and extinguish a firewhen the inner pressure of the gas container reaches a dangerous valueor a flow-blocking safety device for blocking the path of gas flow withthe gas container still installed to extinguish a fire when the innerpressure of the gas container reaches a dangerous value, the hydrostatcomprising: a body comprising a gas outlet, which communicates with thegovernor valve, and a sealed room, which communicate with the gasoutlet; an opening/closing unit which is installed within the sealedroom of the body for opening/closing and closing the gas outlet; anelastic member for biasing the opening/closing unit into a closedposition when the inner pressure of the gas container does not exceed athreshold value and for allowing movement of the opening/closing unit toan open position to discharge gas from the gas container by opening thegas outlet when the inner pressure of the gas container reaches orexceeds the threshold value; and a cap which is fixed at the bottom ofthe body to support the elastic member and the opening/closing unit,wherein the opening/closing unit comprises a sealing shaft with asupport plate at an upper portion thereof, the support plate having acone-shaped top portion; a sealing member comprising a support piecehaving a cone-shaped support groove at the bottom portion thereof forengaging the top portion of the sealing shaft, and a seal piece forblocking the gas outlet when the opening/closing unit is in a closedposition.